Can someone explain me how is possible that the camera or the card replicate files inside the card? It doesn’t happen to all the photos, it’s just a random number of files in the card that are replicated (#4). They have exactly the same name, size, date, etc.

Interesting topic I use the 16GB sandisk without troubles and I never updated my firmware maybe out of laziness. Good to know about this topic though. Firmware updating does not solve your problem Gareth?

i organise by date in lightroom for my pics, and put all my work pics in one folder anyway.

it is obvious to import each client job into a separate folder titled "Jeffries Wedding" etc. and backup to an external folder of the same name at the same time. This is what I will do when I have paying clients.

But I have been keeping the original folders as a backup on my external, and it was nice to have 9999 files in each folder, not some random amount.

I'm talking about the files as well. My D300 has the same behaviour, but I didn't see it until I switched from 4GB to 8GB cards, and then it really threw me for a loop.

For whatever reason, the camera will consider a directory as "full" if it has 999 photos (as opposed to files, in case of NEF+JPEG) in it. It doesn't matter what numbers those photos have, just how many there are in the directory.

I assume you're shooting raw, so you normally can't fit 999 photos on a 16GB card, but can on a 32GB card. (I shoot JPEG, so I saw this at 8GB.)

On your 16GB card, you might shoot say 800 pictures before filling the card up. So you get dsc_0001 to dsc_0800. Then you switch to an empty 16GB card and carry on. There are no photos on this card, so no "full" directories, so you get dsc_0801 to dsc_1600 in the same directory name. And if you never get more than 999 pictures to a card, this continues up to dsc_9999 and then a new directory gets created.

But what if you switch to your 32GB card at dsc_1600? Now you can get say 1600 pictures on a card, which is more than 999. So you shoot away, and at dsc_2599 you have 999 pictures in your directory. At which point the camera decides the directory's full, and creates a new one. But it doesn't reset the picture number, so you get a new directory which starts with dsc_2600.

From page 300 of the manual (I realise it's a bit buried): "Note that a new folder is created automatically if a photograph is taken when the current folder contains 999 photographs." It's not clear from the manual, but that always applies, regardless of any settings.

The D700 is good for 64GB cards as of firmware 1.02. Before that it's rated for 32GB cards I believe.

The camera will only create up to 999 photos in a directory before creating a new one. You're probably getting more because you run out of space and swap cards before reaching that 999 picture limit. Check page 300 of the manual (the description of custom setting d6).